Transcript Is There Life in Space?

Is There Life in Space?
How do scientists study the solar
system?
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Telescopes
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Radiowaves
Infrared
Visible
X-rays
How do telescopes work?
Arecibo Radio Telescope
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Globular cluster M13 was
chosen as a target for
one of the first radio
messages addressed to
possible extraterrestrials.
This message was sent
by the giant radio
telescope of the Arecibo
Observatory in Puerto
Rico, at a ceremony to
mark the remodeling of
the telescope on
November 16, 1973.
What is the Arecibo Message?
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It will take 25,000 years for
the message to reach M13
and if any reply were to be
received it would take
another 25,000 years to
reach Earth, a total of
50,000 years.
The Arecibo message was
more a symbolic event to
demonstrate the
capabilities of the newly
installed equipment than an
actual attempt at
communication.
What does it mean?
What is the origin of our universe?
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Big Bang Theory: As used by cosmologists, the term
Big Bang generally refers to the idea that the Universe
has expanded from a primordial hot and dense initial
condition
Occurred around 13.3 to 13.9 billion years ago and
continues to expand to this day.
What Evidence exists for the Big
Bang Theory?
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First of all, we are reasonably certain that the universe had a beginning.
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Second, galaxies appear to be moving away from us at speeds proportional
to their distance. This is called "Hubble's Law," named after Edwin Hubble
(1889-1953) who discovered this phenomenon in 1929. This observation
supports the expansion of the universe and suggests that the universe was
once compacted.
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Third, if the universe was initially very, very hot as the Big Bang suggests,
we should be able to find some remnant of this heat. In 1965,
Radioastronomers Arno Penzias and Robert Wilson discovered a Cosmic
Microwave Background radiation (CMB) which pervades the observable
universe. This is thought to be the remnant which scientists were looking
for. Penzias and Wilson shared in the 1978 Nobel Prize for Physics for their
discovery.
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Finally, the abundance of the "light elements" Hydrogen and Helium found in
the observable universe are thought to support the Big Bang model of
origins.
How did our solar system form?
Comparing the Planets
Inner Planets: Mercury, Venus, Earth,
Mars (also known as terrestrial planets)
 Outer planets: Jupiter, Saturn, Uranus,
Neptune (also known as gaseous planets
or gas giants)
 Which planet is largest? Smallest?
 How does size affect gravity? Weight?
Mass?
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What other objects exist in our
solar system?
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Asteroids: Any of numerous small celestial bodies
composed of rock and metal that move around the sun
(mainly between the orbits of Mars and Jupiter)
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Comets: A relatively small extraterrestrial body consisting
of a frozen mass that travels around the sun in a highly
elliptical orbit
Structure of a Comet
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Parts of a Comet
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Nucleus: solid part of comet
Coma: A halo of evaporated
gas (water vapor, ammonia,
carbon dioxide) and dust that
surrounds the nucleus
Plasma (Ion) Tail: Electrically
charged gas molecules that
are pushed away from the
nucleus by the solar wind.
Dust Tail: Dust particles that
evaporate from nucleus.
Always faces away from sun!
Where do comets come from?
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The Kuiper Belt is a disk-shaped region past
the orbit of Neptune extending roughly from 30
to 50 AU from the Sun containing many small icy
bodies. It is now considered to be the source of
the short-period comets.
What is the Oort Cloud?
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Comet orbits come in two
varieties, long and short
period.
There are about 600 comets
with known orbits. About 100
have orbits that lie within the
solar system with periods less
than 200 years.
The majority of comets have
long elliptical orbits that are
randomly oriented in space.
These are the long period
comets.
These long period comets
come from a place called the
Oort cloud.
What are meteoroids?
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Meteoroids: Small bodies that travel through space.
They are smaller than asteroids; most are smaller than
the size of a pebble.
Meteors: Meteoroid that has entered the Earth’s
atmosphere.
Meteorites: Meteor that hits the Earth’s surface
WHAT PROPERTIES OF STARS
DO SCIENTISTS STUDY?
COLOR (COMPOSITION)
 TEMPERATURE: RED, ORANGE,
YELLOW, WHITE, BLUE
 MASS
 LUMINOSITY (BRIGHTNESS)
 SIZE (RADIUS)
 AGE
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ANATOMY OF OUR SUN
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Corona: (atmosphere)
Chromosphere (outer
atmosphere)
Photosphere: (inner
atmosphere)
Prominence: arches of gas
Solar Flares: Explosions on
surface
Sun spots: cooler, darker
regions
Nuclear fusion: putting
together atoms
HOW WILL OUR SUN
EVOLVE?
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MEDIUM STARS: RED GIANT TO WHITE DWARF
LARGE STARS: SUPERGIANT, SUPERNOVA,
NEUTRON STAR
MASSIVE STARS: SUPERGIANT, SUPERNOVA,
BLACK HOLE
BIRTH & DEATH OF STARS
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NEBULA: Cloud of dust and gas where stars are born
Black Hole: is a region of space from which nothing, including
light, can escape. It is the result of the deformation of spacetime
caused by a very compact mass.
NEUTRON STAR: A neutron star is about 20 km in diameter
and has the mass of about 1.4 times that of our Sun. This means
that a neutron star is so dense that on Earth, one teaspoonful
would weigh a billion tons!
White Dwarf: A white dwarf is what stars like our Sun become
after they have exhausted their nuclear fuel.
Pulsars: Rotating neutron stars
How do we classify galaxies?
What are comets and asteroids?
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Comets: collection of ice, dust and rocky
particles
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Nucleus: Center solid region
Coma: glowing atmosphere as the comet approaches
the sun
Tail: trail of burning gas and dust particles
Asteroids: debris that did not form planets
Meteoroids: smaller than asteroids
Meteors: when meteoroid enters Earth’s
atmosphere
Meteorites: Any piece that hits Earth’s surface